溶液聚合法制备的氮化碳催化二氧化碳与环氧化合物环加成

CYCLOADDITION OF CARBON DIOXIDE AND EPOXIDE CATALYZED BY CARBON NITRIDE PREPARED THROUGH POLYMERIZATION IN SOLUTION

为提高石墨相氮化碳(g-C_3N_4)的催化活性,以三聚氰胺和三聚氰氯为原料,通过溶液聚合,制备了含有大量表面碱性基团的g-C_3N_4。通过扫描电镜、透射电镜、元素分析、X射线衍射和X射线光电子能谱对所得材料进行了表征。结果表明,与体相g-C_3N_4相比,所得材料具有较低的结晶度和较高的表面胺基含量。将其用于催化二氧化碳与环氧氯丙烷环加成制备环状碳酸酯,并考察了反应条件对催化性能的影响。结果表明,与体相g-C_3N_4相比,所制备的催化剂活性提高了14.8倍。在反应温度140℃、二氧化碳压力3.5 MPa、环氧氯丙烷10mL、ZnBr_2用量1%的条件下反应2h,环氧氯丙烷的转化率可达98.9%,环状碳酸酯的选择性为99.1%。

In order to improve the catalytic activity,graphitic carbon nitride（g-C_3N_4）with a large amount of surface basic groups was prepared by the polymerization of melamine and cyanuric chloride in solution.The as-prepared material was characterized by SEM,TEM,EA,XRD and XPS.The results showed that,compared to bulk g-C_3N_4,the obtained material possesses lower crystallinity and more surface amine groups.Synthesis of cyclic carbonate from the cycloaddition of carbon dioxide and epichlorohydrin was selected to investigate the catalytic performance.The effects of reaction parameters on the catalytic performance were also studied.Under the conditions of 140℃,3.5MPa,10 mL of epichlorohydrin and 1mol%of ZnBr_2,the conversion of epichlorohydrin reached 98.9%after 2hof reaction.The selectivity of cyclic carbonate was 99.1%.